如何在自定义类中注入Laravel 5.2“ Illuminate \\ Http \\ Request”？

Question

I am new to laravel and I got a question here. I am trying to inject 'Illuminate\\Http\\Request' to my custom Class.

Error: __construct() must be an instance of Illuminate\\Http\\Request, none given,

What is wrong with my code below? Thanks!

namespace App\Library;

use Crypt;
use Illuminate\Http\Request;

class MenuAccess
{

    public function __construct(Request $request){
        $this->request = $request;
    }

    public function setLoginSession($user){

       $user = Crypt::encrypt($user);

       $this->request->session()->put('PAZPOSID', $user);

       return $request->session()->pull('PAZPOSID');

    }

}

Answer 1

Based on the error given, you are not passing an instance of Illuminate\\Http\\Request to your constructor.

Because you type hinted your parameter, PHP will enforce and make sure it's the same type being passed in.

More info: http://php.net/manual/en/functions.arguments.php#functions.arguments.type-declaration

You can do a dd($request) before you instantiate your class to see its type.

If you want Laravel IoC to auto resolve it for you, have a look here

Answer 2

This was an exteremely useful question for me. And the answer is very useful.

Laravel dependency injection seems to work ONLY IN functions and constructors that you don't call by hand (like a constructor of a controller, and a closure (function) that is registered as a route)

Try to call by hand the controller constructor which has a dependency injection, and it will NOT WORK.

Here is an example

In routes.php

Route::get('/func_', 'AController@func');

Route::get('/func', function() {
    $c = new App\Http\Controllers\AController;
    return $c->func();
});

Route::get('/f_', 'AController@f');

Route::get('/f', function() {
    $c = new App\Http\Controllers\AController(request());
    return $c->f();
});

Add a controller called AController

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;

class AController extends Controller
{
    public $req;
    public function __construct(Request $req) {
        $this->req = $req;
    }

    public function func() {
        return $this->req->input('name');
    }

    public function f(Request $r) {
        return $r->input('name');
    }
}

And try to run /func_ will work because the controller will be instantiated by Laravel /func will NOT work because you tried to call the constructor yourself /f_ will work because the function which use the dependency injection will be called by Laravel /f will NOT work although you created the controller correctly. But the function will not work because called by hand without parameters

If you want to call a function which has a dependency injection. Call with full parameters

Answer 3

I have found my answer. So the problem is in my controller, I need to instantiate in the construct in my controller before I call my custom class.

And I changed nothing in my Custom Class

Here is what I did to fix it:

use \App\Library\MenuAccess;

class UserController extends Controller
{
    private $menuAccess;

    public function __construct(MenuAccess $menuAccess)
    {
        $this->menuAccess = $menuAccess;
    }

    public function login(Request $request)
    {
        print_r($this->menuAccess->setLoginSession('user@user.com'));
    }
}